An antenna device comprises a carrier, a first radiation portion, a second radiation portion and a coupling portion. The first radiation portion, the second radiation portion and the coupling portion are provided on the carrier. The second radiation portion electrically connects with the first radiation portion. The first radiation portion and the second radiation portion share a shared part, the shared part is directly connected to a reference grounding. The coupling portion capacitively couples an electrical signal to the first radiation portion and the second radiation portion. The first radiation portion and the second radiation portion convert the electrical signal into a radiation signal emitted by the antenna device.